Centering batten for drydocking ships



United States Patent 2,883,752 CENTERING BATTEN FORDRYDOCKING sans Joseph A. Oakley, Garden City, N .Y.

Application June 24, 1957, Serial No. 667,726

16 Claims. (Cl. 33-74) (Granted under Title 35, US. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention concerns a device for indicating the location of a submerged reference. In particular the invention concerns a drydock marker for indicating the location of a submerged keel line established by keel blocks with respect to which a docked ship must be in alignment.

In preparing to drydock a ship it is conventional to empty the drydock of water and to arrange upon the bottom a series of spaced pier blocks that form a cradle upon which the ships bottom will rest.v After the pier blocks are positioned the drydock is flooded and the ship is brought in and set at its approximate location over the blocks. This approximate location is conventionally established by the use of forward and after centering chains that stretch across the dock from one side to the other. Such chains have the disadvantage of requiring considerable time to be set up and the further disadvantage that neither centering chain can be set up until the ship has entered drydock.

The present invention overcomes these disadvantages by providing a buoyant marker hingeable at one endto a keel block, located at the prospective keel line, so that the free end of the marker can float upward and project above the water level to indicate the location of the submerged keel line established by the keelblock.

An object of the invention is to providea device for indicating the location of a submerged reference.

Another object is to provide a drydock marker for indicating the locationof a submerged keel line established by keel blocks with respect to which a docked ship must be in alignment.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing wherein:

Fig. l is a perspective of an indicating device constructed in accordance with the invention and illustrating one embodiment thereof; and

Fig. 2 is a plan in miniature of a drydock having therein sighting indicating devices embodying the invention, such as shown-in Fig. 1 for example, arranged therein in positions for use, and illustrating diagrammatically the manner in which the sighting devices may be used to orient a floating vessel in the drydock in proper position over the pier block. 7 H

In the drawing there is shown aconventional keel block 11 formed of a wood crushing slab 12, a concrete y 13 2 a W an hep p s d keellin 15.

which is shown in broken lines extends longitudinally of block 1 1. I I

Positioned on top of cap 14. isa marker 17 having. a

base, 18 that is fastened securely to cap.14 by dogs 19.

2,883,752 Patented Apr. 28, 1959 A crossarm 20 is hinged on base 18 by means of a pair of hinge elements'21 atthe ends of crossarr'n 20, a second pair of mating hinge elements 22 o'nbasels, and a hinge pin 23. The hinge 9111 23 forms an axis of rotation that is horizontal and that is at rightangles to keel line 15. Fixed to crossarm 20 and extendingjat a right angle therefrom is a rod 24 similar to a surveyors leveling rod that is reinforced by apair of braces 25. Rod 24 is of buoyant construction and preferably is'made of wood. Inscribed on rod 24 are foot markings 26 'for indicating the draft of a ship relative 'to the top of block 11.

Fastened on the back of rod 24 is a pair of U-brackets 31 through which is adapted to slide an extension 32 that can be adjusted upward above the top ofrod 24 for indicating depths greater than those shown on rod 24. Foot markings 33 are inscribed on extension 32. A wing nut 34 serves to lock extension '32 in selected position on rod 24. p v

In the arrangement shown in Fig. 2 the drydock has an enclosure wall 34 with an open end 35, normally closed by a gate 36 that is movable away from closed position, while the chamber 37 of thedrydock is filled with water, to permit a vessel such as indicated in outline by the dash lines 38, to be floated into the chamber 37. The gate is returned to closed position after the vessel has been floated fully into the chamber 37. The special keel blocks 11 with indicators are moved, while the diydock is empty of water, into positions along the floor of the chamber 37 just beyond but close to the desired ends of the vessel when the vessel while floating has been oriented into proper position to settle, upon removing the water from chamber 37, upontheother or regular pier blocks 39 that have been adjusted along the floor of chamber 37 into a sele cte d pattern to support the type and size of the particular vessel.

In operation the drydock is emptied of water in preparation for docking of a ship. A series of spaced pier blocks 39 are then arranged upon the bottom of the drydock in a selected pattern to form a cradle for the ship. Keel block ll is placed in keel line position at the bow or stern and marker. 17 is mounted thereon and fastened by dogs 19. If desired, separate keel blocks 11 can be located in keel line position, one at. the bow andanother at the stern as shown in Fig. 2. The indicator of the rear block 11 should be held down. until after the ship has been floated approximately into desired position. With the drydock empty rod 24 liesin a substantially horizontal position as shown in broken lines on the drawing. If the ships draft is greater than the markings 26 on rod 24, extension 32 is pulled out to an appropriate position and wing nut 34 is tightened. The drydock is then flooded and as the water surface rises the buoyancy of rod 24 of the front blockll causes its free end to float upward so that rod 24 starts erectingabout the axis formed by hinge pin 23, Finally rod 24 is in vertical position with its free end projecting above the water surface. By observing foot markings 26 and. 33 the dock is flooded to a depth exceeding the draft of the ship to be docked.

The ship is then brought into the drydock andset at its approximate location after which rod24 on the rearmost block 11 is released. By observing orsighting on the ship with one or both of the vertical rods 24 the dock ing crew can align the ships keel with the keel, line 15. The ship is then landed on the pier blocks as the dock is pumpeddry. Duringthis operation, after the ship lands on the blocks, the free ends of rods 24 gradually float downward until markers 17' are in substantially horizontal positions when the dock'is empty. 1 I p Buoyant markers 17 have the advantage that they can be arranged in lace before the dock is flooded, and hence before the ship-is brought into the dock. In contrast when using conventional centering chains neither the forward nor the after chain can be hung in place across the dock until after flooding and after the ship has entered the drydock. Markers 17 have the further advantage that they are yieldable and hence are not easily broken. Thus if a buoyant marker 17 should be rammed by the ship being docked or by the docking rowboats, the marker would merely swing about its hinge axis out of the way and then float back into position after the ramming.

If desired, either or both of the buoyant markers 17 may be secured in horizontal position by a line (not shown) secured to the upper level of the drydock prior to flooding to avoid possible damage by the ship or ships when being brought into the drydock. After the ship enters the drydock and has been placed in approximate position over the keel blocks 11, the securing lines may be cut to release the buoyant markers 17 so they can erect into position for final alignment of the ship.

Also, if desired, a line (not shown) may be extended from the top of either or both of the buoyant markers 17 to the ship so that the markers 17 can be held in vertical position until the ship lands on the pier blocks.

Markers 17 have also the advantage of making it easy to arrange many small ships and barges in a large graving dock. By using the buoyant marker the ships do not have to be docked on the centerline of the dock but can be placed at a distance from and an angle to the dock centerline.

Buoyant markers 17 can also be set up in much less time than is required with conventional centering chains.

Buoyant markers 17 may be used in all types of docking operations and in all types of docks; for example, graving docks, marine railways and floating drydocks.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

I claim:

1. A device for visibly indicating above the liquid surface in a floodable drydock having a floor the location of a predetermined reference line at a submergible part of the drydock by which a floating ship may be oriented accurately in said drydock, said device comprising a movable weight which may be moved into different positions over said floor of the drydock and having said reference line, a buoyant element, and means for connecting said element at one end to said weight for movement in a path parallel to a predetermined plane of the base and adapted to be aligned with said reference line, whereby as the liquid surface rises in said drydock said element will move upwardly, the length of said element being greater than the depth of said liquid with the free end of the element extending above the liquid surface to continuously indicate the location of the submerged predetermined reference line at all depths of liquid in said drydock and so that as the liquid surface lowers said element can move downwardly by gravity.

2. A device for visibly indicating above the water surface in a floodable water basin the location of a predetermined reference line at a submergible part of the drydock by which a ship floating in said drydock may be oriented with respect to a desired part of the basin, said device comprising a base having said reference line, an approximately rigid buoyant rod and means for articulately connecting said rod at one end to said base solely for movement between an upright position and an approximate horizontal one, in a path parallel to a predetermined vertical plane of the base and adapted to be aligned with. said reference line, so that as the water surface rises and falls the free end of said rod will appear above the water surface and indicate the location of the submerged predetermined reference line.

3. A device for visibly indicating above the water surface in a floodable drydock the location of a predeten mined place on a submergible pier block, said device comprising said pier block, a buoyant rod, and hinge means connecting said rod at one end to the pier block for swinging movement in one arcuate path only between an upright position and an approximately horizontal position, the length of said rod being greater than the expected depth of water above said pier block, so that as the water surface rises said rod can swing upwardly with the rising water into a vertical position with the free end of the rod always above the water surface and when upright above the predetermined place.

4. In a drydock having a submergible pier block, a device for visibly indicating above the water surface the location of a predetermined place on the submergible pier block, said device comprising a buoyant rod, a hinge having a horizontal axis, means for securing one end of said rod to one element of said hinge and means for securing the other element of said hinge to the pier block, whereby as the water surface rises said rod can swing upwardly into vertical position with the free end of the rod being above the water surface and being above the predetermined place on the submerged pier block.

5. In a drydock having a pier block adapted for alignment with the centerline of a ships bottom, a device for visibly indicating above the water surface the location of the submergible centerline at the pier block, said device comprising a buoyant rod, a hinge having a fixed axis, said hinge being positioned with its axis horizontal and at right angles to the centerline, means for securing one end of said rod to one element of said hinge and means for securing the other element of said hinge to the pier block, whereby as the water surface rises said rod can swing upwardly in an are included in the vertical plane that also includes the centerline with the free end of the rod above the water surface and being above the submerged centerline.

6. The device in claim 5 in which said rod is similar to a surveyors leveling rod and includes an adjustable extension, and means for locking said extension in selected position.

7. The device in claim 5 in combination with depth markings upon said rod for indicating the draft of a ship resting upon the pier block.

8. A device for aiding the orientation of a vessel entering a drydock over a group of pier blocks, which comprises a portable base that can be placed in the drydock in a position spaced lengthwise beyond but adjacent to an end of a vessel within the drydock when the vessel is properly positioned over the group of blocks, said base having greater density than water, and an indicating member articulately connected to said base block for movement thereon into an upright position thereover, said member being floatable in water in which it may be placed into said upright position to serve as a sighting reference element for aid in orienting the vessel into the position desired for it over said group of pier blocks on which it is to be supported when Water is removed from the drydock and the vessel settles on said group of blocks, said member having a length from said special block greater than the maximum expected depth of water above said special block, whereby when said member is upright in the water its top will be visible as a sighting reference to guide one in orienting said vessel in the water of the drydock into the desired position over said group of blocks.

9. A drydock into the water of which a vessel may be floated and then the water removed to expose the entire hull of the vessel, which comprises an enclosure having an opening in a side wall thereof normally closed by a movable gate, and through which opening said vessel may be floated into said enclosure while the gate is open, a group of pier blocks arranged in a selected pattern along the bottom of said enclosure in positions to support the hull of a vessel within the enclosure when the enclosure is emptied of water, and a sighting reference member supported by said enclosure adjacent to the bottom of said enclosure and spaced in a direction lengthwise of the vessel beyond and away from an end of a vessel that is properly positioned over said blocks, said member being movable by the buoyancy thereon of water in said enclosure into an upright position in the water adjacent to said end of the vessel, and having a vertical length suflicient to project above the water level in said enclosure when the vessel was floated in, and serve as a sighting means by which the floating vessel may be properly oriented over said blocks.

10. A device for use as a guide in orienting a vessel in a drydock, into which it has been floated, over a group of pier blocks arranged in a selected pattern on the floor of the drydock and upon which the vessel is expected to rest when the drydock is emptied of said water, which comprises a base having a weight adequate to keep it on said drydock floor when the drydock is filled with water, and movable along said drydock floor into a selected position that will be just beyond, but adjacent to, the end of any vessel floating in said drydock in a position to settle properly on said group of blocks when the dryclock is emptied of said water, and a floatable substantially non-flexible member articulately connected to said base and movable relatively thereto by floating when the drydock is filled with water, into an upright position and having a length from said base adequate, when upright, to extend above the level of the water in said drydock, whereby as the vessel is floated into said drydock one may, by observing the position of the vessel with respect to said upright member, guide the ship into a position in which it will be accurately located in a selected position over said group of blocks.

11. The device as set forth in claim 10, wherein said member is a slender floatable rod hinged to the base for movement thereon about a horizontal axis.

12. The drydock as set forth in claim 9 wherein said member is guided for movement solely in a direction that is within an upright plane parallel to the length of the vessel.

13. The device as set forth in claim 8 wherein said base block rests by gravity on the bottom of the drydock and is movable on said bottom into selected positions for use in orienting difierent types and sizes of vessels in proper positions for support on said group of blocks.

14. The device as set forth in claim 8, wherein said member is hinged to said base block for movement thereon solely in a direction that is within an upright plane parallel to the length of the ship.

15. The device as set forth in claim 13, and wherein said member is hinged to said base block for movement thereon solely in a direction that is within an upright plane parallel to the length of the ship.

16. The drydock as set forth in claim 9, having two of said reference members on the floor of said enclosure one for use at each end of said vessel.

References Cited in the file of this patent UNITED STATES PATENTS 549,281 Timmans Nov. 5, 1895 

